# Change only ONE character in Latex template

I have a book template of Elsevier for which in the math environment the character "v" looks very similar to greek \nu. This causes a lot of misunderstanding and frustration for the readers. I have tried the txfonts package and it solves the problem. Here are the outputs

Since the book is already finished and I cannot replace all the "v" characters with \varv

MY QUESTION IS: Is there any way that I can change the "v" letter with \varv in the Latex template that I have? This will be a lifesaver.

• What font package are you using? Is it mathptmx? – egreg Nov 28 '16 at 10:11
• @egreg On the main file it reads: \documentclass[book,numbers]{elsbook-A07b} \usepackage{amsmath,amssymb,amsfonts,amsthm,makeidx,graphicx} \usepackage{txfonts} \usepackage{helvet} – Amin R. Nov 28 '16 at 10:21
• Another option is to import \nu from Computer Modern. See the middle two lines of this answer: tex.stackexchange.com/a/435722/98394. – Gavin R. Putland Oct 23 '18 at 9:05

Just change the \mathcode of v:

\documentclass{book}

\usepackage{amsmath}
\usepackage{txfonts}

\AtBeginDocument{\mathcodev=\varv}

\begin{document}

A v' in math: $v$

A nu' in math: $\nu$

\end{document}


## Output with the \AtBeginDocument line uncommented

I'd suggest using

\usepackage{newtxtext}
\usepackage[varvw]{newtxmath}


instead of \usepackage{txfonts}. The fonts are essentially the same, but the defects of txfonts are straightened off.

\documentclass{book}

\usepackage{amsmath}
\usepackage{newtxtext}
\usepackage[varvw]{newtxmath}

\begin{document}

A v' in math: $v$

A nu' in math: $\nu$

\end{document}


• Thank you! It solved the issue. Should I use \AtBeginDocument{\mathcodev=\varv} for the case that you suggested in the comments? – Amin R. Nov 28 '16 at 11:18
• @AminR. No, with newtx, you just pass the option varvw (that also changes the w to be similar to v). – egreg Nov 28 '16 at 11:23
• it complains that: 'varvw' undefined in families 'ntxmath'. – Amin R. Nov 28 '16 at 11:29
• @AminR. Update your TeX distribution. The option was added in October 2016. – egreg Nov 28 '16 at 11:40

Supposing you are using:

\usepackage{newtxtext,newtxmath}


The following in your preamble replaces your 'v's in mathmode with the \varv symbol in the output.

\DeclareMathSymbol{v}{\mathord}{lettersA}{51}

\documentclass{article}
\usepackage{newtxtext,newtxmath}
\usepackage[T1]{fontenc}
\DeclareMathSymbol{v}{\mathord}{lettersA}{51}
\begin{document}

This is \verb+\varv+ $\varv$

This is v $v$.

This is greek \verb+\nu+ $\nu$.

\end{document}


• As @egreg noticed, the [varvw] option to newtxmath does that also. You are never too old to learn something new. – Pieter van Oostrum Nov 28 '16 at 11:10